This invention relates to a custom-molded pad for relief of the symptoms of patellar tendinitis. Patellar tendinitis is the inflamation of the patellar tendon at the point at which it attaches to either the inferior pole of the patella or the tibial tuberosity, or the inflamation of the quadriceps tendon at the point at which it attaches to the superior pole of the patella. Patellar tendinitis is primarily caused by continued stress on the patellar or quadriceps tendons. Although repetitive jumping, such as that which occurs while playing volleyball, is an activity commonly associated with aggravating the onset of patellar tendinitis, there are several other activities that can cause the condition, such as running, walking or bicycling. As discussed below, each of these activities involves repetitive use of the same muscle groups and tendons in the legs, which often leads to the inflammation and tearing of the tendons associated with patellar tendinitis.
Standard treatment for a typical case of patellar tendinitis involves resting and applying ice to the affected knee. Non-steroidal anti-inflammatory drugs may also be prescribed to alleviate swelling and pain in the affected area. In many cases, an external device will also be prescribed for use by the patient to support the affected muscles and tendons during normal activities. Such devices help reduce the risk of further injury to the knee. Although it is rare, some severe or chronic cases of patellar tendinitis require arthroscopic or open surgical treatment for tendon decompression or tenodesis.
Prior art methods available for treating patellar tendinitis often fail to provide adequate pain relief. A typical elastic strap used to treat patellar tendinitis extends around the lower leg beneath the knee and seeks to provide concentrated support directly over the patellar tendon. While such devices may provide some degree of generalized support to the injured area, they have limited effectiveness because they provide such support in a manner that inhibits adequate blood flow to the lower limb, and fails to direct concentrated support to the injured area. Any palliative benefits which are actually achieved are quickly offset by the increased pain and numbness in the lower leg caused by pulling the strap too tightly around the leg in an attempt to achieve some degree of support from the device. Those straps which do provide additional padding over the inflamed area are likewise inadequate because the padding is typically so thick that the strap will not conform to the shape of the lower leg without applying an increased amount of pressure over the injured area. This increased pressure causes the padding to compress against the lower leg, and can compromise circulation in the same manner as seen with unpadded straps. Such padded and unpadded elastic straps not only fail to provide concentrated support directly over the injured area, but also fail to provide a secure, custom fit which addresses the unique anatomical needs of the individual wearer.
The knee pad assembly of the present invention is inexpensive to produce, easy to fabricate, comfortable to wear, and offers an improved alternative to conventional elastic bands and other standard treatments for patellar tendinitis. The assembly includes a custom-fitted pad which is molded to conform to the exact shape of the anatomy of a wearer. The pad is first placed against the wearer""s lower leg and cured to a custom-fitted shape. The pad is then secured over or adjacent the inflamed area of the lower leg using an adjustable elastic strap. The strap and the pad cooperate together to provide a custom-fitted device that produces concentrated, radially directed support to the injured tendon without compromising blood circulation to the lower leg. Unlike some prior art knee bands which resort to thick layers of padding in an attempt to provide support, the pad used in the knee pad assembly of the present invention provides adequate support to the injured area by using thin layers of rigid, resin-impregnated fabric. This results in a thin, lightweight pad against which a reduced amount of radially-directed pressure needs to be applied to achieve a higher degree of support to the knee. This promotes blood flow to the injured area and to the lower leg, while accelerating the healing process.
The knee pad assembly of the present invention uses a moisture curable resin system to quickly and easily mold the pad to the shape of the lower leg. Upon curing, the moisture curable resin system yields a very rigid pad having a custom-fitted shape that conforms to the area of the lower leg to which the pad was initially molded. No heat is required to activate curing of the resin. A source of water is the only additional material necessary to achieve a cure. While atmospheric moisture alone will cure the knee pad into its hardened position in a relatively shortened period of time, the resin in or on the pad will typically be activated by immersing the pad in water prior to fitting the pad to an individual""s lower leg. Once a final cure is achieved, the knee pad will maintain its custom-fitted shape regardless of whether the pad is subsequently exposed to heat or moisture.
Therefore, it is an object of the invention to provide a custom-molded knee pad assembly which is easy to fabricate.
It is another object of the invention to provide a knee pad assembly which provides concentrated, radially-directed support to the knee area without compromising circulation of blood to the injured area and to the lower leg.
It is another object of the invention to provide a knee pad assembly that hardens in the presence of moisture to form a very rigid yet very lightweight protective pad.
It is another object of the invention to provide a knee pad assembly that can be quickly and easily positioned on and removed from a wearer""s forearm by the wearer.
It is another object of the invention to provide a knee pad assembly that is stored in a moisture-proof pouch until ready for application to the muscles and tendons to be supported.
These and other objects of the invention are achieved in the preferred embodiments disclosed below by providing a knee pad assembly for relieving the symptoms of patellar tendinitis. The knee pad assembly includes a pad adapted for being positioned against and molded onto a lower leg in the region of the knee for lying in closely-conforming relation against and applying radially-directed pressure to the attachment site of the patellar tendon to the patella, to the knee joint, and to at least one epicondyle of the tibia. The pad is hardened into a rigid structure for therapeutic use, and includes an initially flexible inner substrate impregnated or coated with a reactive system. The system remains stable when maintained in substantially moisture-free conditions and hardens upon exposure to moisture to form a rigid, self-supporting structure having a shape conforming to the lower leg to which the pad is molded during curing. A flexible cover encloses the substrate, and a support cooperates with the pad for maintaining the pad in its closely-conforming position against the lower leg.
According to one preferred embodiment of the invention, the support includes an elongate strap having an outer surface and first and second ends. The first end of the strap is releasably attached to an upper surface of the pad, thereby permitting the strap to extend around the lower leg for securing the pad in the closely conforming configuration against the lower leg.
According to another preferred embodiment of the invention, the inner layer includes a plurality of overlaid thicknesses of fiberglass.
According to yet another preferred embodiment of the invention, the plurality of thicknesses includes at least three and no more than five layers.
According to yet another preferred embodiment of the invention, the outer layer includes an innermost foam layer overlying at least one side of the substrate.
According to yet another preferred embodiment of the invention, the outer layer includes an innermost foam layer enclosing the substrate therein.
According to yet another preferred embodiment of the invention, the foam layer is selected from the group consisting of closed-cell ethylene vinyl acetate and polyurethane.
According to yet another preferred embodiment of the invention, the outer layer further includes a flexible protective cover enclosing the foam layer, wherein the substrate, foam layer and cover are joined together to form a unitary structure for being molded while flexible to an aspect of the lower leg.
According to yet another preferred embodiment of the invention, the cover is formed of a polyester sheeting fabric.
According to yet another preferred embodiment of the invention, the length of the pad is at least twice as great as the width of the pad.
According to yet another preferred embodiment of the invention, the reactive system includes a blended polyisocyanate, polyol, catalyst and stabilizer.
According to yet another preferred embodiment of the invention, the knee pad assembly includes a loop attached to the upper surface and adapted for receiving the strap therethrough for securing the pad against the lower leg.
According to yet another preferred embodiment of the invention, the knee pad assembly includes a first fastener attached to the upper surface for cooperating with a complementary second fastener attached to the strap for holding the pad in place on the lower leg while being worn.
According to yet another preferred embodiment of the invention, one of the first and second fasteners is a patch of looped material, and the other of the first and second fasteners is a complementary patch of hooked material.
According to yet another preferred embodiment of the invention, the first end of the strap includes a fastening ring connected thereto and adapted for receiving said second end therethrough for securing the strap around the lower leg.
According to yet another preferred embodiment of the invention, the knee pad assembly includes a third fastener attached to the second end of the strap for being releasably connected to the outer surface, thereby permitting the strap to be secured around the lower leg.
According to yet another preferred embodiment of the invention, the outer surface of the strap is hook-and-loop material.
According to yet another preferred embodiment of the invention, the third fastener is a patch of hook-and-loop material complementary to the outer surface.
According to yet another preferred embodiment of the invention, a knee pad assembly product for relieving the symptoms of patellartendinitis is provided which includes an outer pouch formed of a moisture-impervious material. A pad is positioned in the pouch in substantially moisture-free conditions and sealed therein against entry of moisture until use. The pad is adapted for being positioned against and molded onto a lower leg in the region of the knee for lying in closely-conforming relation against and applying radially-directed pressure to the attachment site of the patellar tendon to the patella, to the knee joint and to at least one epicondyle of the tibia and hardened into a rigid structure for therapeutic use. The pad includes an initially flexible substrate impregnated or coated with a reactive system. The system remains stable when maintained in substantially moisture-free conditions and hardens upon exposure to moisture to form a rigid, self-supporting structure having a shape conforming to the lower leg to which the pad is molded during curing. A flexible outer layer encloses the substrate, and a support cooperates with the pad for maintaining the pad in its closely-conforming position against the lower leg.